Long-term Monitoring Plan Research Articles

Lack of Impacts during Early Establishment Highlights a Short-Term Management Window for Minimizing Invasions from Perennial Biomass Crops.

Managing intentional species introductions requires evaluating potential ecological risks. However, it is difficult to weigh costs and benefits when data about interactions between novel species and the communities they are introduced to are scarce. In anticipation of expanded cultivation of perennial biomass crops, we experimentally introduced Miscanthus sinensis and Miscanthus × giganteus (two non-native candidate biomass crops) into two different non-crop habitats (old field and flood-plain forest) to evaluate their establishment success and impact on ambient local communities. We followed these controlled introductions and the composition dynamics of the receiving communities over a 5-year period. Habitats differed widely in adult Miscanthus survival and reproduction potential between species, although seed persistence and seedling emergence were similar in the two biomass crops in both habitats. Few introductions survived in the floodplain forest habitat, and this mortality precluded analyses of their potential impacts there. In old field habitats, proportional survival ranged from 0.3 to 0.4, and plant survival and growth increased with age. However, there was no evidence of biomass crop species effects on community richness or evenness or strong impacts on the resident old field constituents across 5 years. These results suggest that Miscanthus species could establish outside of cultivated fields, but there will likely be a lag in any impacts on the receiving communities. Local North American invasions by M. sinensis and M. sacchariflorus display the potential for Miscanthus species to develop aggressively expanding populations. However, the weak short-term community-level impacts demonstrated in the current study indicate a clear management window in which eradicating species footholds is easily achieved, if they can be detected early enough. Diligent long-term monitoring, detection, and eradication plans are needed to successfully minimize harmful invasions from these biomass crops.

Characterization and Comparative Analysis of Ancient Earthen Plasters from the American Southwest

ABSTRACT We have studied earthen plasters and wall materials from three ancient Native American sites in the American Southwest that include a twelfth-century, subterranean kiva used for textile production in Natural Bridges National Monument (Utah), a thirteenth-century, defensive, cliff dwelling at Montezuma Castle (Arizona), and a mid-fourteenth-century, puddled earth Great House at Casa Grande National Monument (Arizona). In each case, the data collected has been used to develop long-term preservation strategies and monitoring plans for each site. To understand the conservation issues, earthen materials were analyzed. Characterization included examination of BSE-SEM micrographs of polished thin sections prepared from a total of 36 samples from the three sites, and XRD of twelve samples. Research goals included: 1) determining the microstructure, micro-composition, porosity, mineralogy of aggregates and phases in the binding matrix for each sample; 2) reconstructing plaster technologies and their variation within and between sites, including material selection, preparation and application sequences, and; 3) identifying principal deterioration conditions and processes. Our findings support the idea that plaster materials were collected locally and manipulated to optimize their performance to suit the unique site conditions and needs of the ancient people using the structures.

Assessing Performance of Leaf Area Index in a Monitored Mountain Ecosystem on Mount Elgon-Uganda

This study investigated the performance of leaf area index (LAI) and photosynthetically active radiation (PAR) in a mountain ecosystem. The authors hypothesized that significant spatial and temporal differences exist in LAI and PAR values in the Manafwa catchment on Mt. Elgon. This was accomplished through field measurements of actual LAI and PAR values of diverse vegetation types along a ~900m altitudinal gradient (1141–2029 masl) in the catchment. In-situ measurements were obtained from 841 micro-scale study plots in 28 sampling plots using high resolution LAI sensors. The findings showed a significant positive relationship exists between elevation and observed LAI (r = 0.45, p = 0.01). A regression model further shows that elevation and curvature of the landscape slope were highly significant (p < 0.00002) predictors of LAI. Finally, the authors detected significant spatial and temporal differences in LAI and PAR values in the study area. The study provides a critical basis for setting up long-term monitoring plans to understand mountain ecosystems and global climate change.

Determination of Heavy Metals in Indoor Dust From Primary School (Sri Serdang, Malaysia): Estimation of the Health Risks

Heavy metal concentrations (Pb, Cd, and Cu) in classroom indoor dust were measured. The health risk (non-carcinogenic) of these heavy metals in classroom indoor dust to children was assessed based on United States Environmental Protection Agency health risk model. Indoor classroom dust samples were collected from 21 locations including windows, fans, and floors at a primary school in Sri Serdang, Malaysia. Classroom dust samples were processed using aqua regia method and analyzed for Pb, Cd, and Cu concentrations. The highest average heavy metal concentrations were found in windows, followed by floor and fan. Pb concentrations ranged from 34.17 μg/g to 101.87 μg/g, Cd concentrations ranged from 1.73 μg/g to 7.5 μg/g, and Cu concentrations ranged from 20.27 μg/g to 82.13 μg/g. Ventilation and cleaning process were found as the possible factors that contributed to heavy metal concentration in window, floor, and fan. Moreover, the hazard index (HI) and hazard quotient (HQ) values for heavy metals Cd and Cu were less than one. By contrast, the HI and HQ values for Pb (maximum values) were more than one, indicating potential non-carcinogenic risk to children. Long-term persistence of leaded petrol, building materials, interior paint, school located near industrial areas and major roads, as well as vehicle emission are the factors attributed to the presence of heavy metals in classroom dust. Further research under a long-term monitoring plan and actual values in a health risk model is crucial before a final decision on heavy metal exposure and its relationship to young children health risks can be made. Nevertheless, the findings of this study provide crucial evidence to include indoor dust quality in school assessment because the environmental processes and impacts of surrounding school area have health risk implications on young children.

Ecological risk assessment for residual coal fly ash at Watts Bar Reservoir, Tennessee.

The Tennessee Valley Authority conducted a Baseline Ecological Risk Assessment (BERA) for the Kingston Fossil Plant ash release site to evaluate potential effects of residual coal ash on biota in Watts Bar Reservoir, Tennessee. The BERA was in response to a release of 4.1 million m(3) of coal ash on December 22, 2008. It used multiple lines of evidence to assess risks for 17 different ecological receptors to approximately 400000 m(3) of residual ash in the Emory and Clinch rivers. Here, we provide a brief overview of the BERA results and then focus on how the results were used to help shape risk management decisions. Those decisions included selecting monitored natural recovery for remediation of the residual ash in the Emory and Clinch rivers and designing a long-term monitoring plan that includes adaptive management principles for timely adjustment to changing conditions. This study demonstrates the importance of site-specific ecological data (e.g., tissue concentrations for food items, reproductive data, and population data) in complex ecological risk assessments. It also illustrates the value of the US Environmental Protection Agency's (USEPA) data quality objectives process in building consensus and identifying multiple uses of results. The relatively limited adverse effects of this likely worst-case scenario for ash-related exposures in a lotic environment provide important context for the USEPA's new coal combustion residue disposal rules.

Climate change sensitivity index for Pacific salmon habitat in southeast Alaska.

Global climate change may become one of the most pressing challenges to Pacific Salmon conservation and management for southeast Alaska in the 21st Century. Predicted hydrologic change associated with climate change will likely challenge the ability of specific stocks to adapt to new flow regimes and resulting shifts in spawning and rearing habitats. Current research suggests egg-to-fry survival may be one of the most important freshwater limiting factors in Pacific Salmon's northern range due to more frequent flooding events predicted to scour eggs from mobile spawning substrates. A watershed-scale hydroclimatic sensitivity index was developed to map this hypothesis with an historical stream gauge station dataset and monthly multiple regression-based discharge models. The relative change from present to future watershed conditions predicted for the spawning and incubation period (September to March) was quantified using an ensemble global climate model average (ECHAM5, HadCM3, and CGCM3.1) and three global greenhouse gas emission scenarios (B1, A1B, and A2) projected to the year 2080. The models showed the region's diverse physiography and climatology resulted in a relatively predictable pattern of change: northern mainland and steeper, snow-fed mountainous watersheds exhibited the greatest increases in discharge, an earlier spring melt, and a transition into rain-fed hydrologic patterns. Predicted streamflow increases for all watersheds ranged from approximately 1-fold to 3-fold for the spawning and incubation period, with increased peak flows in the spring and fall. The hydroclimatic sensitivity index was then combined with an index of currently mapped salmon habitat and species diversity to develop a research and conservation priority matrix, highlighting potentially vulnerable to resilient high-value watersheds. The resulting matrix and observed trends are put forth as a framework to prioritize long-term monitoring plans, mitigation experiments, and finer-scale climate impact and adaptation studies.

Un laboratorio di campo permanente nel Parco Nazionale del Pollino: dinamismo vegetazionale in formazioni prative d'alta quota

By virtue of its ecological and floristic diversity, the Pollino National Park plays a key role for biodiversity conservation in the Mediterranean context. The historical interest of botanists for this areas has provided a lot of descriptive information on its flora and vegetation. Nonetheless, data concerning the effects of current environmental transformations (i.e. land-use changes, climate warming) on local plant richness are still poor. For this reason, the Ente Parco Nazionale del Pollino has promoted a long-term monitoring plan to investigate biodiversity variations in orophylous herbaceous vegetation under two experimental scenarios: absence of grazing, and climate warming. To date, two years of observation revealed significant but contrasting responses in plant communities well differentiated by ecological and floristic features. To better understand the biodiversity variations caused by the experimental regime, the monitoring trials need to be continued over a longer timeframe.

Applying a Watershed-Level, Risk-Based Approach to Addressing Legacy Mercury Contamination in the South River, Virginia: Planning and Problem Formulation

ABSTRACT In 2001, the DuPont Company and various Virginia regulatory agencies (Virginia) established the South River Science Team (SRST) as a multi-stakeholder and collaborative program to address legacy Hg contamination of the South River, Virginia. Specifically, the SRST began to apply a watershed-level risk-based assessment process to evaluate the potential impact of a former DuPont facility adjacent to the South River. Mercury had been found in facility soils in 1976 spawning numerous chemical and biological studies. However, prior to 1999, with the exception of a structured, long-term fish monitoring plan developed by Virginia, these studies were conducted by diverse, independent organizations resulting in limited scientific oversight and implementation, or interaction with the public. This article focuses on some key findings (e.g., defining/refining the issues, setting up the team, the role of the different stakeholders in making the process work) from the problem formulation and planning phase of this multi-stakeholder effort. The SRST effort draws heavily on the concepts of problem formulation (PF) and planning (as described by the U.S. Environmental Protection Agency) to guide the overall risk-based approach. PF is one of the most important steps in the process and, if done correctly can lead to a well-conceived and implemented assessment.

Carbon dynamics in the Amazonian Basin: Integration of eddy covariance and ecophysiological data with a land surface model

Information contained in eddy covariance flux tower data has multiple uses for the development and application of global land surface models, such as evaluation/validation, calibration and process parameterization for carbon stocks and fluxes. In this study, we combine Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA) project data collected from a network of eddy covariance flux towers deployed across the Amazonian basin to improve the carbon stocks and flux estimated by a land surface model, the Integrated Science Assessment Model (ISAM). We evaluate the key model parameters for carbon allocation factors, maintenance respiration as well as the autotrophic respiration using the LBA site measurements. Our model results show that the total biomass ranges from 0.7kgCm−2yr−1 for the pasture site to 20.8kgCm−2yr−1 for the forest site. The ISAM estimates for GPP and NPP are well within the uncertainty range of the site measurement data. Also, the results revealed that all, but one forest site have lower net primary productivity (NPP) to gross primary productivity (GPP) ratio (NPP/GPP=0.4 compared to the savanna and the pasture sites (NPP/GPP=0.5). This is because savanna and the pasture sites experienced the longest dry season and plants growing in such environmental conditions have stronger efficiency to store carbon compared to forests. The forest evergreen site (Km67) has a higher measured NPP/GPP ratio (0.5), because of higher carbon accumulation. Soil carbon is lowest for the pasture site (Km77) (7.2kgCm−2yr−1) and highest for the forest site (Km34) (12.8kgCm−2yr−1). The model results suggest that all the forest sites are a net sink for atmospheric CO2, while the savanna (PDG) and pasture (FNS) sites are neutral and another pasture site (Km77) is net source for atmospheric CO2. Meanwhile, the model results highlight the importance of the LBA site data to improve the model performance for the tropical Amazon region. The study also suggest the need for a network of long-term monitoring plans to measure changes in the vegetation and soil carbon biomass at the local and regional levels. Such programs will be necessary to make reliable global carbon emissions estimates.

Chytridiomycosis in endemic amphibians of the mountain tops of the Córdoba and San Luis ranges, Argentina

Chytridiomycosis is a major threat to amphibian conservation. In Argentina, the pathogenic fungus Batrachochytrium dendrobatidis has been recorded in several localities, and recently, it was registered in amphibians inhabiting low-elevation areas of mountain environments in Córdoba and San Luis provinces. In the present study, we searched for B. dendrobatidis in endemic and non-endemic amphibians on the mountain tops of Córdoba and San Luis provinces. We collected dead amphibians in the upper vegetation belt of the mountains of Córdoba and San Luis. Using standard histological techniques, the presence of fungal infection was confirmed in 5 species. Three of these species are endemic to the mountain tops of both provinces. Although there are no reported population declines in amphibians in these mountains, the presence of B. dendrobatidis in endemic species highlights the need for long-term monitoring plans in the area.

Restoration of overwash processes creates piping plover (Charadrius melodus) habitat on a barrier island (Assateague Island, Maryland)

On Assateague Island, an undeveloped barrier island along Maryland and Virginia, a foredune was constructed to protect the island from the erosion and breaching threat caused by permanent jetties built to maintain Ocean City Inlet. Scientists and engineers integrated expertise in vegetation, wildlife, geomorphology, and coastal engineering in order to design a habitat restoration project that would be evaluated in terms of coastal processes rather than static features. Development of specific restoration targets, thresholds for intervention, and criteria to evaluate long-term project success were based on biological and geomorphological data and coastal engineering models. A detailed long-term monitoring plan was established to measure project sustainability. The foredune unexpectedly acted as near-total barrier to both overwash and wind, and the dynamic ecosystem underwent undesirable habitat changes including conversion of early-succession beach habitat to herbaceous and shrub communities, diminishing availability of foraging habitat and thereby reducing productivity of the Federally-listed Threatened Charadrius melodus (piping plover). To address these impacts, multiple notches were cut through the constructed foredune. The metric for initial geomorphological success—restoration of at least one overwash event per year across the constructed foredune, if occurring elsewhere on the island—was reached. New overwash fans increased island stability by increasing interior island elevation. At every notch, areas of sparse vegetation increased and the new foraging habitat was utilized by breeding pairs during the 2010 breeding season. However, the metric for long-term biological success—an increase to 37% sparsely vegetated habitat on the North End and an increase in piping plover productivity to 1.25 chicks fledged per breeding pair—has not yet been met. By 2010 there was an overall productivity of 1.2 chicks fledged per breeding pair and a 1.7% decrease in sparsely vegetated habitat. Ideally, overwash restoration will sustain the availability of foraging habitat, but future foredune modifications may be necessary to maintain or increase overwash processes and piping plover habitat in the project area.

Tracking Animal Location and Activity with an Automated Radio Telemetry System in a Tropical Rainforest

How do animals use their habitat? Where do they go and what do they do? These basic questions are key not only to understanding a species’ ecology and evolution, but also for addressing many of the environmental challenges we currently face, including problems posed by invasive species, the spread of zoonotic diseases and declines in wildlife populations due to anthropogenic climate and land-use changes. Monitoring the movements and activities of wild animals can be difficult, especially when the species in question are small, cryptic or move over large areas. In this paper, we describe an Automated Radio-Telemetry System (ARTS) that we designed and built on Barro Colorado Island (BCI), Panama to overcome these challenges. We describe the hardware and software we used to implement the ARTS, and discuss the scientific successes we have had using the system, as well as the logistical challenges we faced in maintaining the system in real-world, rainforest conditions. The ARTS uses automated radio-telemetry receivers mounted on 40-m towers topped with arrays of directional antennas to track the activity and location of radio-collared study animals, 24Â h a day, 7 days a week. These receiving units are connected by a wireless network to a server housed in the laboratory on BCI, making these data available in real time to researchers via a web-accessible database. As long as study animals are within the range of the towers, the ARTS system collects data more frequently than typical animal-borne global positioning system collars (~12Â locations/h) with lower accuracy (approximately 50Â m) but at much reduced cost per tag (~10X less expensive). The geographic range of ARTS, like all VHF telemetry, is affected by the size of the radio-tag as well as its position in the forest (e.g. tags in the canopy transmit farther than those on the forest floor). We present a model of signal propagation based on landscape conditions, which quantifies these effects and identifies sources of interference, including weather events and human activity. ARTS has been used to track 374 individual animals from 38 species, including 17 mammal species, 12 birds, 7 reptiles or amphibians, as well as two species of plant seeds. These data elucidate the spatio-temporal dynamics of animal activity and movement at the site and have produced numerous peer-reviewed publications, student theses, magazine articles, educational programs and film documentaries. These data are also relevant to long-term population monitoring and conservation plans. Both the successes and the failures of the ARTS system are applicable to broader sensor network applications and are valuable for advancing sensor network research.

Interagency Monitoring Action Plan (I-MAP) for quagga mussels in Lake Mead, Nevada-Arizona, USA

Following the discovery of quagga mussels in Lake Mead, Nevada-Arizona, USA, a variety of federal, state and regional agencies set up monitoring programs to evaluate and gain information to help minimize the impacts, or potential impacts, of quagga mussels to their facilities and lake ecology. While the agencies have worked closely and shared monitoring data and findings from the beginning of the infestation, there has been no documented comprehensive monitoring program to describe and record the various quagga mussel-related monitoring needs. Ad hoc interagency quagga mussel meeting representatives established an Interagency Monitoring Action Plan (I-MAP), which outlines agency objectives related to quagga mussel monitoring and provides approaches to realize these objectives. I-MAP team members and their respective agencies provide technical, logistical, and financial support in monitoring quagga mussels and their environmental impacts to Lake Mead. The goal of this effort is to develop a long-term, cost-effective, and consistent monitoring plan for quagga mussels in Lake Mead to inform various agencies and to gain efficiencies from shared operations and information. The plan attempts to build upon current monitoring activities and capabilities, identifies the next steps that can occur within existing capabilities and, finally, outlines gaps and areas of future need.

Investigating the Effects of Environmental Change on Arctic Char (<i>Salvelinus alpinus</i>) Growth Using Scientific and Inuit Traditional Knowledge

For centuries, and still today, fishing and hunting of local natural resources have been a source of food and a part of the culture of the Inuvialuit of the Western Arctic region (Fig. 1) (Alunik et al., 2003; Inuvik Community Corporation et al., 2006). The Inuvialuit have attained an intimate and detailed understanding of their surroundings through their own experiences as well as from nearly a thousand years of accumulated observations passed on by their ancestors. This understanding of the local environment, known as traditional knowledge (TK), can provide expert information for the study of climate change effects on northern species (Riedlinger and Berkes, 2001; Furgal et al., 2006; Laidler, 2006) and is being increasingly recognized by the scientific community as a valuable way to understand our environment (Huntington et al., 2004; Hinkel et al., 2007). The direct effects of climate change observed through scientific studies in Canada’s Arctic regions include increasing annual temperatures, unprecedented changes in sea-ice conditions, melting permafrost, and increasing storm events (ACIA, 2004). It is hypothesized that these climate changes will lead to indirect secondary effects on Arctic freshwater and anadromous fishes, resulting in changes to body condition and growth, changes in anadromous behaviours, and losses of local biodiversity due to alterations to habitat (Reist et al., 2006a). The people in the local communities will have to adapt to the potential outcomes of these secondary effects. However, there is a general lack of long-term environmental and faunal data for many of the northern regions of Canada, including the Inuvialuit Settlement Region (ISR) (Reist et al., 2006a), and therefore, a lack of understanding of how the changing climate will ultimately affect northern species. The Inuvialuit of Sachs Harbour and Ulukhaktok (formerly known as Holman), the two northernmost and only permanent island communities in the ISR (Fig. 2), have been noticing unprecedented changes in their environment and local fauna since the mid 1990s and have expressed concern about the impacts of these changes. They have reported that the weather has become “unpredictable” and have observed a suite of rapid environmental changes, which include thinning and melting sea ice, melting permafrost, changes to the seasons, new species occurrences near their communities, and changes in the quality of the Arctic char (Salvelinus alpinus) on which they rely as a source of country food (Riedlinger and Berkes, 2001; Nichols et al., 2004; Barber et al., 2008; Pearce et al., 2009; Sachs Harbour community residents, pers. comm. 2009; Ulukhaktok community residents, pers. comm. 2010). Arctic char is an important biological indicator of climate change in the Arctic because it is the only freshwater fish that has a circumpolar distribution and uses a wide variety of aquatic habitats, including marine, river, and lake environments (Reist et al., 2006b). As the chars are a vital traditional subsistence and economic resource to the Inuit of Canada (Usher, 2002), we need to understand how climate change might affect their condition and populations in Canada’s North. The current importance of Arctic char to Inuvialuit communities and the impending effects of a changing environment necessitate effective long-term community-based monitoring (CBM) plans. CBM supports opportunities for both local study and the collection of scientific data to inform the ongoing inquiry into how environmental stressors affect northern fish species. The purpose of my PhD research is to anticipate and demonstrate the secondary effects of climate variability on Arctic char and provide understanding of these effects to FIG. 1. Margaret Kanayok, a resident of Ulukhaktok, Northwest

Load Rating and Reliability Analysis of an Aerial Guideway Structure for Condition Assessment

Aerial guideways are elegant transportation structures that are seen at airports, theme parks, and crowded urban areas. The guideways generally consist of continuous, prestressed concrete beam spans, precast concrete columns, and steel beam-column connections. Although there are guidelines prepared as a supplement to conventional highway and railway bridge design codes, aerial guideways form a different class, relatively less studied compared to common highway bridges. The primary objective of this paper is to present a study to better understand the structural behavior and capacity used in an existing guideway structural system which has been in service for about 35 years. The load demand on the guideway system has increased by about 50% over the years. The structural system is composed of six-span continuous prestressed concrete bridge segments. In order to develop models that bound the possible existing condition of the structure, several models are developed by changing the most critical parameters. The critical parameters are categorized as material properties, prestress losses, boundary conditions, and continuity conditions. Sensitivity studies are conducted using eight parametric models for simulations with moving loads for the two different train types. The load rating and reliability indexes are computed for all the cases under different loading conditions. The parameters that have the most influence on the load rating and reliability are also presented. The information generated from these analyses can be utilized for better-focused visual inspection and can also be used for developing a long-term structural monitoring plan.

Assessment of lake sensitivity to acidic deposition in national parks of the Rocky Mountains

The sensitivity of high-elevation lakes to acidic deposition was evaluated in five national parks of the Rocky Mountains based on statistical relations between lake acid-neutralizing capacity concentrations and basin characteristics. Acid-neutralizing capacity (ANC) of 151 lakes sampled during synoptic surveys and basin-characteristic information derived from geographic information system (GIS) data sets were used to calibrate the statistical models. The explanatory basin variables that were considered included topographic parameters, bedrock type, and vegetation type. A logistic regression model was developed, and modeling results were cross-validated through lake sampling during fall 2004 at 58 lakes. The model was applied to lake basins greater than 1 ha in area in Glacier National Park (n = 244 lakes), Grand Teton National Park (n = 106 lakes), Great Sand Dunes National Park and Preserve (n = 11 lakes), Rocky Mountain National Park (n = 114 lakes), and Yellowstone National Park (n = 294 lakes). Lakes that had a high probability of having an ANC concentration <100 microeq/L, and therefore sensitive to acidic deposition, are located in basins with elevations >3000 m, with <30% of the catchment having northeast aspect and with >80% of the catchment bedrock having low buffering capacity. The modeling results indicate that the most sensitive lakes are located in Rocky Mountain National Park and Grand Teton National Park. This technique for evaluating the lake sensitivity to acidic deposition is useful for designing long-term monitoring plans and is potentially transferable to other remote mountain areas of the United States and the world.

Population Assessment of the Pacific Green Spiny Lobster Panulirus gracilis in Pacific Panama

Populations of the green spiny lobster Panulirus gracilis (Streets 1871) have sustained increasing harvesting pressure in Pacific Panama for decades, but basic information about their biology and ecology in the region is scarce. This study provides baseline data for the densities and biometrics of P. gracilis in Las Perlas and Coiba Archipelagos. The number of surveyed lobsters in both archipelagos was surprisingly low (85 in Las Perlas and 67 in Coiba), and average densities were dismal (4.1 ± 8.8 ind. ha−1 and 5.3 ± 7.6 ind. ha−1, respectively). Saboga and San Jose Islands had the highest relative densities of P. gracilis in Las Perlas, whereas intermediate relative densities were found only on Coiba Island in the Coiba Archipelago. Lobster density was not associated with either substrate or depth. In Las Perlas, female carapace length (CL) was 40–95 mm and that of males was 25–100 mm; in Coiba, female CL was 45–124 mm and male CL was 45–121 mm. In Las Perlas, the smallest lobster with eggs had a CL = 65 mm and a tail length (TL) = 120 mm, whereas the smallest in Coiba had a CL = 60 mm and a TL = 81–115 mm. We recommend implementing: (1) the minimum capture CL as the average carapace length at which half of the lobster population from Coiba is adult (CL = 84 mm; TL = 112–155 mm); (2) a fishing season no longer than 6 mo; (3) management decisions involving local fishermen and native peoples; (4) marine reserves or no-take areas (NTA); and (5) long-term monitoring plans, as the best current options to insure the survival of P. gracilis in the region.

Mercury Biogeochemical Cycling and Bioaccumulation in Aquatic Environments: A Review

Over the last century the mercury (Hg) concentration in the environment has been increased by human activities with inputs from sources such as atmospheric deposition, urban runoff, and industrial effluents. Mercury can be transformed to methylmercury (MeHg) in anaerobic conditions by sulfate reducing bacteria (SRB) and sediments are the principal location for MeHg production in aquatic environments. Interest in bioaccumulation of Hg and MeHg into lower trophic levels of benthic and pelagic organisms stems from public health concerns as these organisms provide essential links for higher trophic levels of food chains such as fish and larger invertebrates. Fish consumption is the major exposure route of MeHg to humans. Recently, it was reported that blood samples in Korea showed much higher Hg levels (5-8 times) than those in USA and Germany. Although this brings much attention to Hg research in Korea, there are very few studies on Hg biogeochemical cycling and bioaccumulation in aquatic environments. Given the importance of Hg methylation and MeHg transfer through food chains in aquatic environments, it is imperative that studies should be done in much detail looking at the fate, transport, and bioaccumulation of Hg and MeHg in the environment. Moreover, there should be long-term monitoring plans in Korea to evaluate the environmental and health effects of Hg and MeHg.

Performance Assessment and Monitoring of a Permeable Reactive Barrier for the Remediation of a Contaminated Site

The present study illustrates the long-term monitoring plan carried out in order to investigate the performance of a zero-valent iron permeable reactive barrier (PRB) at a chlorinated solvents’ site. The cleanup intervention has been undertaken at an industrial landfill located near the city of Turin (Italy) and represents the first full-scale application of this technology in Italy. The monitoring plan started in November 2005 with the aim to verify the attainment of the cleanup goals and to evaluate the efficiency status of the PRB. Controls focuses not only on contaminant monitoring but also on the hydraulic and chemical conditions created by the barrier, in order to evaluate potential long term effects of secondary biogeochemical processes (e.g. mineral precipitation, microbiallymediated redox transformation, gas accumulation) on PRB performance. The monitoring plan provides controls on groundwater chemistry (target contaminants and geochemical indicators) and core sampling for mineralogical analysis of zero-valent iron by X-ray diffraction and scanning electron microscopy. The first, partial results of the monitoring activity are illustrated. Monitoring data clearly indicate that the plume is being adequately captured and treated in order to accomplish the clean-up goals with a good safety margin. However, it results that mineral precipitation and gas phase accumulation could determine, over time, a decreasing in hydraulic conductivity and porosity of the barrier, thus modifying the flow field through the reactive cell. Besides the monitoring controls, further investigations will be performed to assess the occurring microbial process and to evaluate their impact on PRB performance.

Strategies and Decision-Support Tools for Optimizing Long-Term Groundwater Monitoring Plans—MAROS 2.0

ABSTRACT Existing long-term groundwater monitoring programs can be optimized to increase their effectiveness/efficiency with the potential to generate considerable cost savings. The optimization can be achieved through an overall evaluation of conditions of the contaminant plume and the monitoring network, focused spatial and temporal sampling analyses, and automated and efficient management of data, analyses, and reporting. Version 2.0 of the Monitoring and Remediation Optimization System (MAROS) software, by integrating long-term monitoring analysis strategies and innovative optimization methods with a data management, processing, and reporting system, allows site managers to quickly and readily develop cost-effective long-term groundwater monitoring plans. The MAROS optimization strategy consists of a hierarchical combination of analysis methods essential to the decision-making process. Analyses are performed in three phases: 1) evaluating site information and historical monitoring data to obtain local concentration trends and an overview of the plume status; 2) developing optimal sampling plans for future monitoring at the site with innovative optimization methods; and 3) assessing the statistical sufficiency of the sampling plans to provide insights into the future performance of the monitoring program. Two case studies are presented to demonstrate the usefulness of the developed techniques and the rigor of the software.